How to implement “prevUntil” in Vanilla JavaScript without libraries?

Question

I need to implement the functionality of jQuery\'s prevUntil() method in Vanilla JavaScript.

I\'ve got several

elements on the same level:

Answer 1

You could use indexOf to determine if the index of the siblings are less than the index of the target element:

// jshint esversion: 9

// get the target node
const node = document.querySelector("div:nth-child(3)");

// get the target node's index
const node_index = node.parentNode.indexOf(node);

// get the siblings of the target node
const siblings = node => [...node.parentNode.children].filter(child => 
  child !== node
);
console.log(siblings);

// get the prevUntil
const class_name = "\bmy_class\b";
const prevUntil = siblings.filter((sibling, i) =>
  i < node_index && (sibling.getAttribute("class") || "").includes(class_name)
);
console.log(prevUntil);

Good luck.